Keppra (Levetiracetam) dosage. Keppra and its generic form come in 250 mg, 500 mg, 750 mg and 1,000 mg tablets as well as in a grape flavored liquid (100 mg/mL). Keppra XR extended release tablets are available in 500 mg and 750 mg. It’s not necessary to eat before taking Keppra. Your required dose will depend on your age, condition, dosage form, and kidney function. It’s important that Keppra tablets be swallowed whole and not chewed or crushed.